Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds real behavioral context beyond that: the result ordering is newest-change-first and the corpus is limited to the public catalogue. It stops short of describing pagination or the meaning of the limit parameter.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two tightly written sentences: the first front-loads what the tool returns and in what order, the second handles routing. No filler or repetition of the name/title.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema exists, so return values need not be explained. Purpose, scope, ordering and the sibling alternative are all present; the only gap is the absence of any statement about the limit parameter's effect or default.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The single parameter 'limit' has 0% schema description coverage and is not mentioned anywhere in the description. The schema's default/min/max make it largely self-explanatory, but the rubric requires the description to compensate at low coverage, and it does not (e.g. it never says how many results are returned by default or how to page).

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('List the most recently added or updated German flea markets'), plus the scope ('public my-flohmarkt.de catalogue') and ordering ('newest change first'). This is clearly distinguishable from get_event and search_events without opening any schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly names the use case ('see what is new without a search query') and the alternative with its selecting condition ('use search_events when you know the city, PLZ, date range or area'). Both when-to-use and when-not-to-use are covered.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.